Private Client, Tadley, Hampshire

Installation of bespoke sewage treatment plant

MJ Abbott were contacted by the client to provide a comparable quotation against two other contractors. After visiting the site and listening to the client's account of the two previous sewage plants failing in only 13 years, it was soon clear that an “off the shelf” sewage treatment plant was just not going to be the solution.

The client advised that originally a septic tank had been installed at the site, which only lasted 18 months before failing. This was replaced by a sewage treatment plant which had lasted 11 years before being forced up and out of the ground after the anchor plates gave way.

Following the excavation of trial holes, it was soon apparent that the subsoil below 2 metres was a very soft and sloppy clay. Further investigations proved that the house itself had been constructed on a concrete pile and ring beam system.

MJ Abbott highlighted the danger of any new sewage treatment plant being forced out of the ground, or tipping in the ground, due to the poor soil structure. We advised that we could have a bespoke sewage treatment plant manufactured for the client by our supplier Synergy Wastewater Treatment Products, which would be able to cope with the ground conditions of the site.

The bespoke sewage plant was manufactured at a maximum diameter of 1.2m with an inlet at the very top to reduce the maximum installation depth. Due to the requirement to operate at a shallow depth a “two tank” system was adopted, with primary settlement, bio zone and secondary settlement with sludge return.

MJ Abbott dealt with the Building Control department at the local council and ensured the bespoke sewage treatment plant was approved by the Environment Agency, before completing the installation within time and on budget.

Our client was very pleased with the final result, and can relax in the knowledge that his new sewage treatment plant will provide many years of efficient service.